Many disposable medical devices such as continuous ambulatory peritoneal dialysis (CAPD) disposable sets, blood bags, I.V. solution containers, therapeutic fluid delivery sets, administrative sets for blood, and the like are made of a flexible, collapsible polyvinyl chloride plastic. Alternatively, polyolefin type and other materials have been proposed for use as a substitute for polyvinyl chloride plastic. See, for example, Gajewski et al., U.S. Pat. No. 4,140,162, which discloses polyolefin-type blends for making flexible, collapsible containers.
It may be desirable in many instances to manufacture products, for example medical devices, in which some of the device is made of one type of plastic, for example a polyolefin, while another part of the device is made of a different type of plastic such as polyvinyl chloride. For example, it may be desirable for blood bag made from PVC to be connected to an administration set of a polyvinyl chloride formulation. It may also be desirable to connect a tubing segment of PVC to a non-PVC tubing.
Unfortunately, PVC is adhesively incompatible with most polyolefin-type materials, so that the maintenance of a sealed, sterile connection between the incompatible materials is a substantial technical problem.
Attempts have been made to solve this by various mechanical seals, for example, see Vcelka and Winchell U.S. Pat. No. 4,049,034. However, these mechanical techniques for sealing incompatible materials all involve structure having increased complexity and expense over simpler seals, usable when the materials to be sealed are compatible.
Coupling devices have also been fabricated from polymeric blends for connecting incompatible materials. For example, U.S. Pat. No. 4,327,726 discloses a polymer blend of 13% polypropylene, 35% polyester elastomer (Hytrel), 13% ethylene vinyl acetate copolymer and 39% SEBS. This polymer blend can be molded into a connector which is capable of simultaneously sealing to both PVC and polyolefin plastics.
In Canadian Patent No. 1,194,246 discloses a polymer blend for making a coupler for joining PVC to polyolefin materials. The polymer blend has from 1-8% polypropylene, 35%55% polyester elastomer (Hytrel), 0-15% EVA and 40-65% SEBS.
In accordance with this invention, polymer blends are disclosed which are capable of being formed into a connector member for sealing to both PVC and polyolefin plastics, or other adhesively incompatible materials.
As a result of this, various devices, and specifically medical devices, may be fabricated with various parts made of dissimilar materials and connected together in accordance with this invention.